MAINTAINERS: update cxgb4 and cxgb3 maintainer

Vishal Kulkarni will be the new maintainer for Chelsio cxgb3/cxgb4
drivers.
Signed-off-by: Arjun Vynipadath <arjun@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -4123,7 +4123,7 @@ S:	Maintained
 F:	drivers/media/dvb-frontends/cxd2820r*
 
 CXGB3 ETHERNET DRIVER (CXGB3)
-M:	Arjun Vynipadath <arjun@chelsio.com>
+M:	Vishal Kulkarni <vishal@chelsio.com>
 L:	netdev@vger.kernel.org
 W:	http://www.chelsio.com
 S:	Supported
@@ -4152,7 +4152,7 @@ S:	Supported
 F:	drivers/crypto/chelsio
 
 CXGB4 ETHERNET DRIVER (CXGB4)
-M:	Arjun Vynipadath <arjun@chelsio.com>
+M:	Vishal Kulkarni <vishal@chelsio.com>
 L:	netdev@vger.kernel.org
 W:	http://www.chelsio.com
 S:	Supported